<?php
/*
	Class : Emogrifier
	Author: http://www.pelagodesign.com/sidecar/emogrifier/
	Konvertuesi i extern-CSS ne inline-CSS  
*/
	class Emogrifier {
	
	    private $html = '';
	    private $css = '';
	    private $unprocessableHTMLTags = array('wbr');
	
	    public function __construct($html = '', $css = '') {
	        $this->html = $html;
	        $this->css  = $css;
	    }
	
	    public function setHTML($html = '') { $this->html = $html; }
	    public function setCSS($css = '') { $this->css = $css; }
	
		// there are some HTML tags that DOMDocument cannot process, and will throw an error if it encounters them.
		// these functions allow you to add/remove them if necessary.
		// it only strips them from the code (does not remove actual nodes).
	    public function addUnprocessableHTMLTag($tag) { $this->unprocessableHTMLTags[] = $tag; }
	    public function removeUnprocessableHTMLTag($tag) {
	        if (($key = array_search($tag,$this->unprocessableHTMLTags)) !== false)
	            unset($this->unprocessableHTMLTags[$key]);
	    }
	
	    // applies the CSS you submit to the html you submit. places the css inline
		public function emogrify() {
		    $body = $this->html;
		    // process the CSS here, turning the CSS style blocks into inline css
		    if (count($this->unprocessableHTMLTags)) {
	            $unprocessableHTMLTags = implode('|',$this->unprocessableHTMLTags);
	            $body = preg_replace("/<($unprocessableHTMLTags)[^>]*>/i",'',$body);
		    }
	
	        $encoding = mb_detect_encoding($body);
	        $body = mb_convert_encoding($body, 'HTML-ENTITIES', $encoding);
	
	        $xmldoc = new DOMDocument;
			$xmldoc->encoding = $encoding;
			$xmldoc->strictErrorChecking = false;
			$xmldoc->formatOutput = true;
	        $xmldoc->loadHTML($body);
			$xmldoc->normalizeDocument();
	
			$xpath = new DOMXPath($xmldoc);
	
	        // before be begin processing the CSS file, parse the document and normalize all existing CSS attributes (changes 'DISPLAY: none' to 'display: none');
	        // we wouldn't have to do this if DOMXPath supported XPath 2.0.
	        $nodes = @$xpath->query('//*[@style]');
	        if ($nodes->length > 0) foreach ($nodes as $node) $node->setAttribute('style',preg_replace('/[A-z\-]+(?=\:)/Se',"strtolower('\\0')",$node->getAttribute('style')));
	
			// get rid of css comment code
			$re_commentCSS = '/\/\*.*\*\//sU';
			$css = preg_replace($re_commentCSS,'',$this->css);
	
			// process the CSS file for selectors and definitions
			$re_CSS = '/^\s*([^{]+){([^}]+)}/mis';
			preg_match_all($re_CSS,$css,$matches);
	
	        $all_selectors = array();
			foreach ($matches[1] as $key => $selectorString) {
			    // if there is a blank definition, skip
			    if (!strlen(trim($matches[2][$key]))) continue;
	
	            // else split by commas and duplicate attributes so we can sort by selector precedence
			    $selectors = explode(',',$selectorString);
			    foreach ($selectors as $selector) {
	                // don't process pseudo-classes
			        if (strpos($selector,':') !== false) continue;
	                $all_selectors[] = array('selector' => $selector,
	                                         'attributes' => $matches[2][$key],
	                                         'index' => $key, // keep track of where it appears in the file, since order is important
	                );
	            }
	        }
	
	        // now sort the selectors by precedence
	        usort($all_selectors, array('self','sortBySelectorPrecedence'));
	
	        foreach ($all_selectors as $value) {
	
	            // query the body for the xpath selector
	            $nodes = $xpath->query($this->translateCSStoXpath(trim($value['selector'])));
	
	            foreach($nodes as $node) {
	                // if it has a style attribute, get it, process it, and append (overwrite) new stuff
	                if ($node->hasAttribute('style')) {
	                    // break it up into an associative array
	                    $oldStyleArr = $this->cssStyleDefinitionToArray($node->getAttribute('style'));
	                    $newStyleArr = $this->cssStyleDefinitionToArray($value['attributes']);
	
	                    // new styles overwrite the old styles (not technically accurate, but close enough)
	                    $combinedArr = array_merge($oldStyleArr,$newStyleArr);
	                    $style = '';
	                    foreach ($combinedArr as $k => $v) $style .= (strtolower($k) . ':' . $v . ';');
	                } else {
	                    // otherwise create a new style
	                    $style = trim($value['attributes']);
	                }
	                $node->setAttribute('style',$style);
	            }
	        }
	
			// This removes styles from your email that contain display:none. You could comment these out if you want.
	        $nodes = $xpath->query('//*[contains(translate(@style," ",""),"display:none")]');
	        foreach ($nodes as $node) $node->parentNode->removeChild($node);
	
			return $xmldoc->saveHTML();
	
		}
	
	    private static function sortBySelectorPrecedence($a, $b) {
	        $precedenceA = self::getCSSSelectorPrecedence($a['selector']);
	        $precedenceB = self::getCSSSelectorPrecedence($b['selector']);
	
	        // we want these sorted ascendingly so selectors with lesser precedence get processed first and
	        // selectors with greater precedence get sorted last
	        return ($precedenceA == $precedenceB) ? ($a['index'] < $b['index'] ? -1 : 1) : ($precedenceA < $precedenceB ? -1 : 1);
	    }
	
	    private static function getCSSSelectorPrecedence($selector) {
	        $precedence = 0;
	        $value = 100;
	        $search = array('\#','\.',''); // ids: worth 100, classes: worth 10, elements: worth 1
	
	        foreach ($search as $s) {
	            if (trim($selector == '')) break;
	            $num = 0;
	            $selector = preg_replace('/'.$s.'\w+/','',$selector,-1,$num);
	            $precedence += ($value * $num);
	            $value /= 10;
	        }
	
	        return $precedence;
	    }
	
		// right now we only support CSS 1 selectors, but include CSS2/3 selectors are fully possible.
		// http://plasmasturm.org/log/444/
		private function translateCSStoXpath($css_selector) {
		    // returns an Xpath selector
		    $search = array(
		                       '/\s+>\s+/', // Matches any F element that is a child of an element E.
		                       '/(\w+)\s+\+\s+(\w+)/', // Matches any F element that is a child of an element E.
		                       '/\s+/', // Matches any F element that is a descendant of an E element.
		                       '/(\w+)?\#([\w\-]+)/e', // Matches id attributes
		                       '/(\w+|\*)?((\.[\w\-]+)+)/e', // Matches class attributes
		    );
		    $replace = array(
		                       '/',
		                       '\\1/following-sibling::*[1]/self::\\2',
		                       '//',
		                       "(strlen('\\1') ? '\\1' : '*').'[@id=\"\\2\"]'",
		                       "(strlen('\\1') ? '\\1' : '*').'[contains(concat(\" \",@class,\" \"),concat(\" \",\"'.implode('\",\" \"))][contains(concat(\" \",@class,\" \"),concat(\" \",\"',explode('.',substr('\\2',1))).'\",\" \"))]'",
		    );
		    return '//'.preg_replace($search,$replace,trim($css_selector));
		}
	
		private function cssStyleDefinitionToArray($style) {
		    $definitions = explode(';',$style);
		    $retArr = array();
		    foreach ($definitions as $def) {
	            if (empty($def) || strpos($def, ':') === false) continue;
	    	    list($key,$value) = explode(':',$def);
	    	    if (empty($key) || empty($value)) continue;
	    	    $retArr[trim($key)] = trim($value);
		    }
		    return $retArr;
		}
	}
?>